Catálogo de publicaciones - revistas

<jats:title>Sorting out cell sorting</jats:title> <jats:p> The sorting of proteins into appropriate compartments is vital for proper cell function. After its discovery 20 years ago, various potential roles for nascent chain-associated complex (NAC) in the specificity of intracellular protein sorting have been proposed. Until now, no clear phenotypes have been discovered. Gamerdinger <jats:italic>et al.</jats:italic> explored the role of NAC in protein translocation in <jats:italic>Caenorhabditis elegans</jats:italic> (see the Perspective by Kramer <jats:italic>et al.</jats:italic> ). They found that NAC prevents the importation of incorrect cargo, such as mitochondrial proteins, into the endoplasmic reticulum. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6231" page="201" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa5335">201</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6231" page="182" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aab1335">182</jats:related-article> </jats:p>

<jats:title>Detecting multiple temperatures</jats:title> <jats:p> Most people have an intuitive understanding of temperature. In the context of statistical mechanics, the higher the temperature, the more a system is removed from its lowest energy state. Things become more complicated in a nonequilibrium system governed by quantum mechanics and constrained by several conserved quantities. Langen <jats:italic>et al.</jats:italic> showed that as many as 10 temperature-like parameters are necessary to describe the steady state of a one-dimensional gas of Rb atoms that was split into two in a particular way (see the Perspective by Spielman). </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6231" page="207" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.1257026">207</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6231" page="185" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa8070">185</jats:related-article> </jats:p>

<jats:title>Imaging lipid composition</jats:title> <jats:p> Chemical imaging of cell membranes can be performed with matrix-assisted laser desorption/ionization mass spectrometry (MALDI), but low ionization efficiency often leads to a signal dominated by the main lipid components, such as abundant phosphatidylcholine species. Soltwisch <jats:italic>et al.</jats:italic> used a tunable laser for post-ionization of neutral species to boost the signal for other membrane components, such as cholesterol and phospho- and glycolipids. Imaging of cells and tissues with these methods allows differentiation based on a more extensive chemical signature. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6231" page="211" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa1051">211</jats:related-article> </jats:p>

<jats:title>Benchmarking quantum simulation</jats:title> <jats:p> Finding a solution to a problem often amounts to an optimization problem and thus can be recast in terms of the lowest-energy state of a system. To find such ground states, mathematical methods based on annealing were developed. To reach the ground state more quickly than with the earlier classical methods, a quantum-mechanical approach was proposed; however, the evidence for quantum speed-up is contradictory. Heim <jats:italic>et al.</jats:italic> show that the results depend on how the problem is described and how the optimization routine is implemented. This development should be valuable for benchmarking quantum machines. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6231" page="215" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa4170">215</jats:related-article> </jats:p>

<jats:title>Mapping Mars' water history</jats:title> <jats:p> We know the water cycle on Earth is complex. Neither is it simple on Mars. Infrared maps of water isotopes made by Villanueva <jats:italic>et al.</jats:italic> show the distribution of H <jats:sub>2</jats:sub> O and “semiheavy” water (HDO: deuterated water containing a mixture of hydrogen isotopes) across Mars. HDO enrichment varies with time and location; for example, irregular isotopic signals associate with different terrain features. The measurements also allow seasonal sublimation levels of the northern ice cap to be estimated and thus could be used to reveal past climate behavior. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6231" page="218" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa3630">218</jats:related-article> </jats:p>